1. Field of the Invention
This invention relates to mountaineering equipment and more particularly concerns a shovel blade attachment adapted to be affixed to a climber""s ice axe.
2. Description of the Prior Art Climbing in snow is a fundamental part of mountaineering. Climbers like snow for several reasons: a) it makes many climbs easier by providing a pathway over brush and other obstacles on the approach hike, b) it reduces the danger of loose rock on the ascent, and c) it brings beauty to the mountains and conceals the impact of people upon the environment.
Snow is a complex medium that shows up in many forms that continually change, making snow travel considerably more difficult than trail hiking or rock climbing. Snow falls in forms that vary from flakes, to tiny crystals to coarse pellets, depending on temperature and wind. Once fallen, snow begins to change as it is acted upon by sun, wind, temperature variations, self-compaction, and subsequent precipitation. Even in the course of a day, the snow can change from rock hard in the morning to thigh-sucking slush in the afternoon, and back again by evening.
The ice axe is one of the most versatile and important pieces of mountaineering equipment a climber owns. Without it, safe alpine travel is restricted to easy scrambles. With an axe, and the skill to use it, the climber can venture onto all forms of snow and ice, enjoying a greater variety of mountain landscapes during more seasons of the year.
The modern ice axe is an inherently simple tool with many uses. Below the snow line, it is used for balance, as a walking cane, and to help brake going downhill. But its main role is in snow and ice travel, where it provides balance and a point of security or safety to prevent or arrest a fall. It is also used to chop steps in icy snow for foot holds, and can be used as a brake for a controlled sliding technique known as glissading. Furthermore, it can become a snow anchor when buried in the snow.
The ice axe has several parts: 1) the head, which includes a) the pick, namely a pointed protrusion, and b) the adze, a curved flat scoop extending opposite the pick, 2) the shaft, a rounded or oval tube of various lengths made of aluminum alloy, titanium or a composite material, and 3) the spike, a sharp steel tip on the opposite end of the shaft from the head.
The pick on most ice axes is curved or drooped, a design that provides better hooking action in snow or ice, causing the axe to dig in faster when trying to stop oneself after a fall. A moderate hooking angle of 65 to 70 degrees from the shaft is typical for general mountaineering uses. A sharper angle of 55 to 60 degrees is commonplace for technical ice climbing, as it coincides with the arc followed by the axe head when it is planted in steep ice. Some ice climbing axes permit adjustable bolted pick angles. However, most ice axes are used for snow climbing, and have a moderate hooking angle of 65 to 70 degrees. The head is made of xe2x85x9 to {fraction (3/16)} steel alloy stamped out before hardening. The adze part of the ice axe is either attached before hardening by welding or simply formed by a quarter turn of the heat-softened head.
The most critical function of the ice axe is a maneuver referred to as self-arrest. Self-arrest is the lifesaving technique of using the ice axe to stop the climber""s uncontrolled or accidental slide down a snow slope. If unroped, it offers the only chance to stop the slide. It is the single most important snow-climbing skill. The technique also serves to brace a climber solidly in the snow if he has to hold the fall of a rope-mate. Therefore, a climber""s own life and those of fellow climbers could hinge on self-arrest.
In the self-arrest maneuver, the hands hold the axe in a solid grip, one hand with thumb under the adze and fingers over the pick, the other hand on the shaft just above the spike. The pick is pressed into the snow just above the climbers shoulder so that the adze is near the angle formed by the neck and shoulder. The shaft crosses the chest diagonally and is held close to the opposite hip. Gripping the shaft near the end prevents that hand from acting as a pivot around which the spike can swing to jab the thigh. The chest and shoulder are pressed strongly down on the ice-axe shaft. The climber""s spine is arched slightly away from the snow. This arch is critical; it places the bulk of the climber""s weight on the axe head and on his toes or knees, the points that dig into the snow to force a stop.
A common problem experienced by climbers occurs when a climb is being made along a steep, near vertical surface in soft snow, semi-firm snow or soft crust. If the snow were solidly packed or ice, the climber would simply use the axe in the above manner.
However on this softer type snow the above self arrest technique does not work. The pick head may be sunk into the snow to its fullest extent, and the falling climber continues to accelerate. The narrow pick simply cannot generate enough drag or braking force to slow the person. Even the adze does not have enough area to provide significant braking force. The spike is the only part that can generate enough braking force by being sunk deeply into the snow. However the only safe way to hold this position is in a sitting glissade position which is not considered a safe self arrest position.
The book: Mountaineering, Freedom of the Hills, 5th edition (considered the xe2x80x9cbiblexe2x80x9d of mountaineering) contains an illustration on page 289 indicating that rolling toward the spike for self arrest is incorrect while also stating on that same page under xe2x80x9cVariationsxe2x80x9d that the greatest possible drag from the ice axe on loose snow may be in this position. Thus a danger does exist by losing control on this position. It is for these types of snow that this invention is proposed. Snow conditions vary from hard ice, where even a very sharp pick has difficulty penetrating, to very loose xe2x80x9cpowderxe2x80x9d where an ice axe may not be needed at all to stop a fall. Actually, mountaineers may encounter both in the course of a winter climb along with all types in between.
Another mountain climbing skill performed with the ice axe is self-belay. It is usually performed on gentle to semi-steep slopes with the spike used like a walking cane for control and an anchor point for a slip. On steep slopes, a climber can make a direct assault by chopping the pick into the snow and pulling with the arms while climbing with the legs. (Commonly known as xe2x80x9cclimbing on all foursxe2x80x9d). The pick serves as the anchor point if the legs slip.
Ice climbers use two small ice climbing axes (one in each hand) and crampons on their boots to work their way up a slope xe2x80x9con all fours.xe2x80x9d Again, this technique does not work on semi-firm snow, soft snow or soft crust, since the narrow pickhead pulls too easily through the snow. This problem is also resolved by this invention.
Two other ice axe functions are enhanced by virtue of the improvement of the present invention. The first is a technique known as glissading. Glissading, as mentioned earlier, is a self-controlled slide down a snow slope, most commonly done in a sitting position (which is its most stable and safe position) wherein the spike is dug into the snow for braking purposes. It is an easy and enjoyable way to descend hard to semifirm snowfields which have enough angle to the slope to slide. This invention provides an additional position for soft or semifirm snow wherein the shovel attachment is employed for braking effect.
The second function improved by virtue of the present invention is that wherein the ice axe is used as a snow anchor. Climbers frequently use snow anchors and pickets for attaching ropes to belay. The ice axe can be buried vertically or horizontally (as a xe2x80x9cdead man anchorxe2x80x9d) in the snow for rope attachment. The present invention enables the ice axe to be used as a snow anchor by burying or sinking the entire unit beneath the snow and attaching a rope to the handle.
A broad-bladed shovel is another utility and safety tool for snow travel. It is the only practical tool available for uncovering an avalanche victim. Shovels are also used for digging snow shelters and leveling off tent platforms, and have been used as a climbing tool to shovel a pathway up a particularly snowy route.
A good snow shovel has a blade large enough to move snow efficiently, and a handle long enough for good leverage but short enough for use in a confined area. Some snow shovels come with a detachable handle or with a blade that locks perpendicular to the handle so it can be used as a trenching tool. For projects such as building snow caves, mountaineers sometimes carry a grain scoop, a broad-bladed shovel that can move a lot of snow.
Mountaineers are extremely conscious of the weight and bulk of equipment that they carry because it represents added effort and encumbrance in climbing. Therefore, the need to carry an extra shafted tool such as a shovel must be weighed against its encumbrance.
Numerous shovel adapters have earlier been disclosed. Various blades have been employed in attempts to extend the versatility of hammers, picks, scrapers and other tools. For example, U.S. Pat. No. 4,475,756 to Reading discloses a Shovel adapter for a geologist""s hammer. The blade has a plurality of slots adapted to receive the pick end of the hammer which is secured in place with locking hardware. By virtue of the design of the shovel blade and locking hardware, the adapter cannot be quickly deployed in a configuration that would be useful to climbers.
U.S. Pat. No. 3,334,939 to Bonic discloses a combination snow shovel and ice scraper in which the shovel blade may be locked into place upon the scraper blade. Neither of the aforementioned shovel devices are amenable to use with an ice axe.
U.S. Pat. No. 827,898 to Wiener discloses a shovel blade attachment for a bayonet of a rifle. The shovel can only be disposed in line with the rifle, and employed for digging purposes.
U.S. Pat. No. 3,404,412 to Ryan describes a shovel attachment blade adapted to be disposed in line with the handle of a hatchet.
U.S. Pat. No. 5,345,635 issued to Morgan discloses a shovel attachment for a climber""s ice axe. However the shovel attachment can be secured only in a position orthogonal to the shaft of the ice axe, enabling the assembly to be useful as a belaying tool, but not permitting use in a conventional shoveling manner.
It is accordingly an object of the present invention to provide a spade attachment for an ice axe which permits use of the ice axe as a shovel or trenching tool while enhancing its gripping ability in loose snow in self-belaying and self-arresting maneuvers.
It is another object of the present invention to provide a spade attachment of the aforesaid nature which may be quickly and easily deployed and removed.
It is still another object of this invention to provide a spade attachment of the aforesaid nature which is lightweight, durable, and amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.
The above and other beneficial objects and advantages are accomplished in accordance with the present invention by a shovel blade attachment for an ice axe having a handle shaft elongated upon a center axis and a head affixed thereto, said head having an adze extremity and opposed pick extremity, said attachment comprising:
a) a blade of monolithic construction having upper and lower surfaces, opposed side edges, and front and rear edges, whereby the blade is symmetrically configured about a plane that vertically intersects the blade in parallel disposition to said side edges and midway therebetween, and a straight slot centered upon said plane of symmetry and extending from said rear edge toward said front edge,
b) a V-shaped securing saddle downwardly directed from said lower surface, and spanning said slot,
c) a flat V-shaped receiving pocket disposed upon said upper surface adjacent said rear edge spanning said slot and communicating therewith, and containing an aperture centered upon said plane of symmetry, and
d) threaded securement means adapted to penetrate said aperture.
In a preferred embodiment, forward retaining means in the form of a bar is disposed beneath said lower surface forwardly of said saddle and in perpendicularly spanning disposition across said slot. The receiving pocket preferably serves the further purpose of structurally reinforcing the blade adjacent the rear edge where weakness might otherwise be expected because of the presence of the slot. In a further embodiment, the securing saddle is formed as a tab downwardly bent from the blade as a continuous integral extension thereof. The forward retaining means may further be in the form of a tab upwardly bent from the blade as a continuous integral extension thereof. Said front edge is preferably bilaterally forwardly tapered, and said rear edge preferably has a retaining lip downwardly directed from said lower surface.
The present invention further embraces the combination of the aforesaid shovel blade attachment and an ice axe modified in a manner to interact optimally with the shovel blade attachment.